* Owner's Manual: The most reliable source is your truck's owner's manual. It should have a detailed diagram showing the location of both the underhood and interior fuse panels, along with what each fuse protects.
* Ford's Website: Ford's official website might have owner's manuals available for download, even for older models like the 1999 F-150. Search their site using "1999 F-150 owner's manual."
* Online Repair Manuals: Websites like Haynes and Chilton offer repair manuals (often for a fee) that include detailed fuse box diagrams and other technical information.
* Third-Party Automotive Websites: Some automotive parts websites (like AutoZone or Advance Auto Parts) may have online diagrams or downloadable PDFs if you enter your vehicle's year, make, and model. However, the accuracy can vary.
* YouTube: While not always the most reliable, some YouTube videos may show the fuse box location and provide a visual guide, but don't rely solely on this method for identifying the function of each fuse.
Important Note: When working with fuses and electrical systems, always disconnect the negative battery terminal first to prevent electrical shock or damage to your vehicle's electrical system.
